I haven't worked out this out fully yet, but it seems that linking or annotating newly added text that contains accented or non-Latin characters frequently causes those characters to disappear. Re-adding them in the same word almost always results in their turning into pawns when, anywhere else on the page, the link dialog is subsequently opened or a link is inserted.
This happens everywhere on a page including body text, tables and image captions.
Version: unspecified
Severity: critical
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=53747